Claude Opus 4.8 vs Z.ai: GLM 5.1
Side-by-side comparison. Updated 2026-06-09.
Verdict
Claude Opus 4.8 wins on higher overall score (9.7 vs 9.1, +0.6).
- Larger context window (1000k vs 202k)
At a Glance
| Attribute | Claude Opus 4.8 | Z.ai: GLM 5.1 |
|---|---|---|
| Provider | Anthropic | Z Ai |
| Tags | general | Intelligent Coding Agentic |
| Context | 1,000,000 tokens | 202,752 tokens |
| Input price | $15.00/1M | $0.98/1M |
| Output price | $3.08/1M | $3.08/1M |
| Input modalities | Text | Text |
| Output modalities | Text | Text |
Claude Opus 4.8 Strengths
- Best-in-class reasoning depth
- Superior coding ability
- Strong agentic task performance
- Consistent long-running work handling
- 1M token context window
Z.ai: GLM 5.1 Strengths
- Top-tier coding and long-horizon task completion
- Strong agentic reasoning for multi-step workflows
- Configurable reasoning depth for cost/quality tradeoffs
- Excellent instruction following on complex tasks